Not sure - it seems that every well-known police murder case ended with a multi-million-dollar settlement, even though officers were often acquitted. Wikipedia has details on these.

Qualified immunity only stops people from suing the individual police officers, and they don't even have enough money to pay out multi-million dollar settlements anyway. The big payouts come from suing the police department itself as an instituation and as I understand it they aren't protected by qualified immunity.